The clip library has one forward locomotion cycle and no strafe or
backpedal clips, so a character sidestepping ran forwards on the spot
while sliding sideways. Nothing in the animation said which way they were
travelling and a body lean was carrying the whole burden of telling the
player.
Yaw the HIPS onto the travel direction and unwind it up the spine. The
legs hang off the hips, so the whole stride turns with them and it costs
no new animation; the chest keeps facing roughly where the player aims.
Past about a right angle the hips cannot follow, so the cycle plays in
reverse and the legs point the other way — a real backpedal instead of a
moonwalk. The regime is hysteretic and the yaw is eased, so crossing
between them reads as a pivot, which is what a person does there.
The lean moved into the travel frame with it. Leaning "forward" along the
facing while the legs run off to one side leans them sideways relative to
their own stride, which is what being dragged rather than running feels
like. It is also driven by how hard the character is moving rather than
by signed forward input, so a sidestep leans into its own stride instead
of standing straight up.
debug/travel_dir_check.gd measures it. How far the stride points from the
actual direction of travel:
forward 9° fwd-diagonals 5-6° backpedal 2° back-diagonal 2°
pure sidestep 39-42°, which is the deliberate hip cap
Two things worth knowing about that tool. It reads bone poses from inside
the modifier pass, because Godot restores them afterwards and anything
read later is the animation with the pose layer missing. And it averages
over a full stride: a run cycle twists the torso against the hips by tens
of degrees twice per stride, so a single-frame sample measures the clip,
not the layer.
Co-Authored-By: Claude Opus 5 <[email protected]>
Nicholas Butzke